Brazilian Agroindustrial Wastes as a Potential Resource of Bioative Compounds and Their Antimicrobial and Antioxidant Activities

The study of the recovery of bioactive compounds from natural resources and its implications in several areas is very significant for the scientific community. This work aimed to study Brazilian agroindustrial wastes' antioxidant and antimicrobial activities using green extraction. Olive leaves, jaboticaba peel, araca peel, and pecan nut shells were evaluated under four conditions: (1) convective-drying and aqueous extraction, (2) convective-drying and ethanolic extraction, (3) freeze-drying and aqueous extraction, and (4) freeze-drying and ethanolic extraction. The results demonstrated that all samples showed high antioxidant potential, and the highest antioxidant activity was obtained for the extract of pecan nut shell. As for the quantification of compounds by HPLC, the olive leaf presented the highest content of phenolic compounds in the extract, mainly oleuropein. Finally, the antimicrobial activity analysis revealed the extracts' bactericidal potential against Staphylococcus aureus and Escherichia coli. The present study shows that green extraction can extract bioactive compounds with antioxidant and antimicrobial properties, highlighting the importance of choosing the drying method and solvent for future uses of these natural resources by the industry.